Field of the Invention
The present invention pertains to a hatch cover and latching mechanism for locking the cover in a closed position. The hatch cover is particularly adapted for railroad hopper car hatches and the like.
Background
In the art of hatch covers for railway car loading hatches and other related applications there have been several developments directed to providing covers which have latching mechanisms to minimize the chance of the hatch cover flying open when the latching mechanism is released due to fluid pressure build-up inside the car hopper. U.S. Pat. Nos. 2,745,362 to E. O. Lunde; 4,126,094 to James R. Zimmerle et al.; 4,248,160 to John L. Carney, Jr. et al.; 4,388,873 to John V. Carlton et al.; and 4,441,431 to John L. Carney et al. are examples of hopper car hatch covers wherein a generally circular cover is disposed over a cylindrical hatch, is connected to a hinged support bar and incorporates a latching mechanism for securing the cover in a closed position. Even with the development of the hatch covers described in the aforementioned patents, there are certain desirable features in railcar hatch covers and the like which have not been provided by prior art.
One desirable feature in a railcar hatch cover is a latching mechanism which is operable to securely latch and lock the cover in a closed position and which is operable to minimize the chance of unwanted violent opening of the hatch upon release of the latch mechanism in the event of pressure buildup inside the car hopper. Still other features which have been deemed desirable to provide in railcar hatch covers include a latching mechanism which is relatively easy to engage and disengage and which includes a latch member, for example, which may easily be engaged with the hatch in the partially closed position to draw the hatch downward to compress a gasket type seal and also, with minimum effort, move the latch member into a locking position wherein a latching cam or the like securely engages a cooperating member which is supporting or connected to the hatch cover.
It has further been determined that it is desirable to provide a hatch cover with means to minimize the chance of impacting the roof of the car tank or hopper to prevent chipping the exterior finish or damaging interior linings or coatings for the hopper. Still other features which are considered desirable are the provision of a relatively low profile of the hatch cover, the cover hinge and the latch mechanism in both open and closed positions. It is to this end that the present invention has been developed in an effort to meet all of the desiderata described herein as well as other features which will be apparent to those skilled in the art.